Letter re: EPA/DEP WTC dust cleanup at 114 Liberty Street,

NYC 9/11 Public Portal Document

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These comments are also being transmitted to Ihe EPA Office of the Inspector General (OIG), because they augment those charges presented to the OIG in my 7/4/03 report on the WTC clean­ up.'

114 Liberty St. Building History Building history prior to 9/11/01 The 114 Liberty St. building is an eleven floor building on the south border of Ground Zero, which dates from the turn of the century. In 1998, the upper 9 floors were converted from office space to residential condominiums. Commercial tenants in the first two and one half floors remained intact during the renovation.

Before the renovation, the upper floors had vinyl asbestos tiles. The ceilings were plastered brick vaults between steel I-beams. The lower floor commercial spaces had and continue to have dropped loose tile grid ceilings. The lower floor commercial spaces have a separate cooling and ventilation system. All spaces share a steam heating system.

The renovation and conversion to condominiums covered all the floor tiles with new flooring, primarily wood, with some areas of stone or ceramic tiles.

The ceiling was lowered with drywall suspended from the original steel beams on the ceilings. This created an open space above the suspended ceiling which is used for the return air flow for the ventilation and air conditioning system. Non-asbestos fireproofing was sprayed onto the original ceilings before installing die suspended drywall.

Damage and contamination caused by the WTC collapse All of the front windows, and a few in the rear of the building, were broken by the WTC blast. Tn the rooms in front of the building facing Ground Zero, there were inches of WTC dust. Towards the rear of the building, the dust layers were not as thick, with a coating of around % inch or less.

The ventilation system was operating that day, and thus pulled a large amount of dust throughout the system, including the open return air system above the suspended drywall ceilings. The spaces between the walls of the residential units (drywall construction using galvanized steel supports) provided an open path to the space above the ceiling. WTC dust penetrated into these wall spaces as well as into the plenum above the ceiling.

There was structural damage on the face of the building approximately 20 feet high by 40 feet wide, where the building was hit by larger pieces of the collapsing WTC. Iron beams were bent, and bricks were loosened. At the center of the damage, there was a hole spanning 3 window widths from floor to ceiling.

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